Lidar and Movable Device

The present application claims the benefit of priority to Chinese Patent Application No. 202410407316.6, filed on Apr. 3, 2024, which is hereby incorporated by reference in its entirety.

The present application relates to the technical field of laser detection equipment, and in particular to a LiDAR and a movable device.

LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. Its working principle is to measure relevant information of the target object, such as target distance, direction, altitude, speed, attitude, and even shape, by emitting laser signals through the transmitting module and detecting the echo signal of the target object through the receiving module.

For coaxial TOF (Time of Flight) LiDAR, since the surface transmittance of the device on the light transmission path is difficult to reach 100%, there is always a certain reflectivity, which will cause part of the light inside the LiDAR to be reflected back before it is emitted to the outside of the LiDAR and reach the detector, generating the leading light. The existence of the leading light will affect the detection results of the LiDAR.

Embodiments of the present application provide a LiDAR and a movable device, which are configured to improve the problem in the related art that the presence of the leading light affects the detection results of the LiDAR.

In a first aspect, the embodiment of the present application provides a LiDAR, including: a housing, a transmitter, a receiver, a beam splitter and a first extinction device, where the transmitter is located in the housing, and the transmitter is configured to emit emission light. The receiver is located in the housing, and the receiver is configured to receive the echo light. The beam splitter is located in the housing, and the beam splitter includes a light-transmitting portion and a light-reflecting portion connected to the light-transmitting portion, the light-transmitting portion is configured to receive the emission light emitted by the transmitter, and transmit the emission light to the target object outside the housing; the light-reflecting portion is configured to receive the echo light reflected by the target object outside the housing, and transmit the echo light to the receiver. The first extinction device is located in the housing, along the transmission path of the echo light, the first extinction device is located between the beam splitter and the receiver, and the first extinction device is configured to block the optical signal in the non-primary optical path regions from being transmitted to the receiver, where in the optical signal in the non-primary optical path regions, the energy proportion of the echo light is less than the first preset value.

In a second aspect, the embodiment of the present application provides a movable device, including: a device body and the above-mentioned LiDAR, where the device body is connected to the LiDAR.

The LiDAR and movable device of the embodiments of the present application are equipped with a first extinction device between the beam splitter and the receiver, and the first extinction device is configured to block the optical signal in the non-primary optical path regions from being transmitted to the receiver, thereby preventing the stray light in the non-primary optical path regions from being received by the receiver, reducing the influence of the stray light on the detection results of the LiDAR, and improving the detection accuracy of the LiDAR; and because the energy of the echo light in the non-primary optical path regions accounts for a small proportion, even if the receiver does not receive this part of the echo light energy, it will hardly affect the detection performance of the LiDAR.

Reference signs:

In order to make the objectives, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

The embodiment of the present application provides a LiDAR, where the LiDAR may be a TOF LiDAR, which detects characteristics such as the distance of a target object based on measuring the time (flight time) that light travels between the LiDAR and the target object.

Referring to, the LiDARincludes a housing, a transmitter, a receiver, a beam splitterand a first extinction device. The transmitter, the receiver, the beam splitterand the first extinction deviceare all located in the housing, where the transmitteris configured to emit emission light, the receiveris configured to receive echo light, the beam splitterincludes a light-transmitting portionand a light-reflecting portionconnected to the light-transmitting portion, the light-transmitting portionis configured to receive the emission light emitted by the transmitter, and transmit the emission light to the target object outside the housing; the light-reflecting portionis configured to receive the echo light reflected by the target object outside the housing, and transmit the echo light to the receiver. Along the transmission path of the echo light, the first extinction deviceis located between the beam splitterand the receiver, and the first extinction deviceis configured to block the optical signal in the non-primary optical path regions from being transmitted to the receiver. The optical signal in the non-primary optical path regions, the energy proportion of the echo light is less than the first preset value. It should be noted that the first preset value can be selected according to actual needs; for example, the first preset value can be 6%, 8%, 10%, 12%, 14%, etc., without limitation.

The above-mentioned first extinction deviceis set between the beam splitterand the receiver, and the first extinction deviceis configured to block the optical signal in the non-primary optical path regions from being transmitted to the receiver, so as to prevent the stray light (such as the leading light) in the non-primary optical path regions from being received by the receiver, thereby reducing the influence of the stray light on the detection result of the LiDARand improving the detection accuracy of the LiDAR; and because the energy of the echo light in the non-primary optical path regions accounts for a small proportion, even if the receiverdoes not receive this part of the echo light energy, it will hardly affect the detection performance of the LiDAR.

It is understandable that when determining the specific installation position of the first extinction device, it is necessary to first determine the non-primary optical path regions between the beam splitterand the receiver. The non-primary optical path regions between the beam splitterand the receivercan be obtained by fitting the light path through the simulation system. In some embodiments, the optical path between the beam splitterand the receivercan be fitted through the simulation system, and the energy proportion of the echo light at each region in the optical path between the beam splitterand the receivercan be obtained, and the primary optical path regions and non-primary optical path regions can be divided according to the energy proportion of the echo light. In the optical signal in the primary optical path regions, the energy proportion of the echo light is greater than or equal to the second preset value. The second preset value can be selected according to actual needs; for example, the second preset value can be 86%, 88%, 90%, 92%, 94%, etc., without limitation.

The first extinction devicecan be configured only to block the optical signal in the non-primary optical path regions from being transmitted to the receiver. The first extinction devicecan also be configured to block the optical signal in the non-primary optical path regions from being transmitted to the receiver, and to block the optical signal in the primary optical path regions close to the edge of the non-primary optical path regions from being transmitted to the receiver, so as to obtain a better effect of eliminating optical crosstalk.

It should be noted that if the first extinction deviceis also configured to block the optical signal of the edge primary optical path regions from being transmitted to the receiver, the region ratio of the edge primary optical path regions in the primary optical path regions can be less than or equal to the third preset value, so as to better eliminate the effect of optical crosstalk while ensuring that the echo light energy received by the LiDARis sufficient. The third preset value can be selected according to actual needs; for example, the third preset value can be 26%, 28%, 30%, 32%, 34%, etc., which is not limited.

Furthermore, the first extinction portionis configured to block the optical signal transmitted to the receiverthrough the light-transmitting portion. Since the optical signal transmitted to the receiverby the light-transmitting portiondoes not belong to the echo light, the first extinction portionis designed to block the optical signal transmitted to the receiverthrough the light-transmitting portion, so as to eliminate the crosstalk of the optical signal transmitted to the receiverby the light-transmitting portionto the echo light. The optical signal transmitted to the receiverthrough the light-transmitting portionmay be located in the non-primary optical path regions.

It should be noted that in the actual manufacturing process, it is difficult for the light-transmitting components (such as the light-transmitting portionof the beam splitter, the window pane, and the transceiver module) to achieve a 100% light transmittance, and there will always be a certain reflectivity, which will cause the emission light to reach the receiverafter a certain transmission inside the housingwithout emitting from the housing, that is, the leading light is generated, and the leading light will cause crosstalk to the echo light received by the receiver. The leading light is mainly transmitted inside the housing, and the transmission time is similar to the detection time of the close-range target object, which is easy to affect the detection accuracy of the close-range target object and cause a detection blind spot for the close-range target object. In some embodiments, the reasons for the generation of the leading light include: first, referring to, part of the emission light emitted by the light-transmitting portionis reflected by the light-transmitting components (such as the window pane, the transceiver module) on the transmission path, and returns to the light-transmitting portionbefore it is emitted from the housingto reach the target object, and is at least partially reflected by the light-transmitting portiontoward the receiver; second, referring to, part of the emission light emitted by the transmitteris not transmitted through the light-transmitting portionbut is reflected by the light-transmitting portion, and is reflected back to the light-transmitting portionagain by the components on the reflection path (such as the housing), and then is transmitted through the light-transmitting portiontoward the receiver. That is, at least part of the leading light will be emitted to the receiverthrough the light-transmitting portion. Based on this, referring to, the above design includes a first extinction device, which comprises a first extinction portion. The first extinction portionis used to block optical signals transmitted through the light-transmitting portionto the receiver, thereby eliminating the influence of at least part of the stray light. This enhances the detection accuracy of the LiDARfor close-range target objects and improves the detection field of view of the LiDAR, and improving the detection field of view of the LiDAR.

In an exemplary embodiment, the first extinction devicemay include only the first extinction portion. In another exemplary embodiment, referring toand, the first extinction deviceincludes, in addition to the first extinction portion, a second extinction portion. The light-reflecting portionis disposed around the periphery of the light-transmitting portion, the second extinction portionis disposed around the periphery of the first extinction portion, and a light-passing portionis formed between the second extinction portionand the first extinction portion, and the light-passing portionis configured to pass the optical signal transmitted to the receiverthrough the light-reflecting portion. The second extinction portionmay be configured to block the light of a large angle from being transmitted to the receiver. The light of a large angle may be located in a non-primary optical path regions, and the optical signal transmitted to the receiverthrough the light-reflecting portionmay be located in primary optical path regions.

The above-mentioned first extinction portioncan be roughly circular, square, runway-shaped, etc., without limitation. The second extinction portioncan be roughly circular, square, runway-shaped, etc., without limitation. In the actual design process, the shapes of the first extinction portionand the second extinction portioncan be determined by the shape of the non-primary optical path regions.

The light-passing portioncan be roughly circular, square, runway-shaped, etc., without limitation. In the actual design process, the shape of the light-passing portionmay be determined by the shape of the primary optical path regions. The light-passing portionmay be a light-through hole, or a structure made of a light-transmitting material, without limitation.

It should be noted that, referring to, the first extinction portionand the second extinction portionmay be separated from each other. Referring to, the first light extinction portionand the second extinction portionmay also be partially connected, which is not limited thereto.

The first extinction portionand the second extinction portionmay be made of a material having a reflectivity less than or equal to a fourth preset value. The fourth preset value may be selected according to actual needs; for example, the fourth preset value may be 1%, 3%, 5%, 7%, 9%, etc., which is not limited thereto.

The first extinction devicecan be arranged at any position between the beam splitterand the receiver. For example, the LiDARalso includes a receiver lens group, which includes at least one receiver lens. The receiver lens groupis located in the housing, and along the transmission path of the echo light, the receiver lens groupis located between the beam splitterand the receiver. In an exemplary solution, referring to, along the transmission path of the echo light, a first extinction deviceis arranged between the beam splitterand the receiver lens group. In another exemplary solution, referring to, the receiver lens groupincludes a plurality of receiver lensesarranged at intervals, and along the transmission path of the echo light, a first extinction deviceis arranged between two adjacent receiver lenses. In another exemplary solution, referring to, along the transmission path of the echo light, a first extinction deviceis arranged between the receiver lens groupand the receiver. Of course, at least two of the above three situations can also be selected to exist at the same time. In this case, the number of the first extinction deviceis multiple, and the embodiment of the present application does not limit this. It should be noted that if the LiDARincludes multiple first extinction device, all of the first extinction devicescan include the first extinction portionand the second extinction portion, or all of the first extinction devicecan include the first extinction portionbut not the second extinction portion, or some of the first extinction devicecan include the first extinction portionand the second extinction portion, and the remaining first extinction devicecan include the first extinction portionbut not the second extinction portion, and this is not limited.

In some embodiments, if a first extinction deviceis provided between the beam splitterand the receiver lens groupalong the transmission path of the echo light, the first extinction devicecan be designed with fewer factors to be considered, the allowed design tolerance can be larger, and the design requirements are lower, which is conducive to reducing the manufacturing cost of the LiDAR. For example, along the transmission path of the echo light, the first extinction devicebetween the beam splitterand the receiver lens groupcan be designed according to the caliber of the beam splitterand the divergence angle of the echo light. If the first extinction deviceis provided between two adjacent receiver lensesand/or the first extinction deviceis provided between the receiver lens groupand the receiver, the first extinction portionof the first extinction deviceneeds to be designed according to the caliber of the beam splitter, the divergence angle of the echo light and the focal length of the receiver lens, and the focal length of the receiver lensneeds to be considered, the allowed design tolerance is smaller, and the design requirements will be higher. Based on this, during actual production and manufacturing, the position of the first extinction devicecan be selected in combination with actual needs to meet at least one of the above three situations.

Referring toand, the first extinction devicemay include a light extinction sheet, and the light extinction sheet is spaced apart from the receiver lens groupalong the transmission path of the echo light. Since the light extinction sheet does not need to be attached to the receiver lens, the size of the light extinction sheet does not need to be matched with the receiving surface and/or the emitting surface of the receiver lens, and the design can be more flexible. In some embodiments, the receiving surface of the receiver lensis configured to receive the echo light, and the emitting surface of the receiver lensis configured to emit the echo light.

In some embodiments, if a first extinction deviceis provided between the beam splitterand the receiver lens groupalong the transmission path of the echo light, then the first extinction deviceis provided between: a receiving surface of the receiver lens groupclosest to the beam splitterand the beam splitter. If a first extinction deviceis provided between two adjacent receiver lensesalong the transmission path of the echo light, then the first extinction deviceis provided between: an emitting surface of a receiver lensclose to the beam splitterand a receiving surface of a receiver lensfar from the beam splitteramong the two adjacent receiver lenses. If a first extinction deviceis provided between the receiver lens groupand the receiveralong the transmission path of the echo light, then the first extinction deviceis provided between: an emitting surface of the receiver lens groupclosest to the receiverand the receiver.

Referring to, the first extinction devicemay include a extinction layer, and the extinction layer is attached to the receiver lens, that is, the first extinction deviceis directly arranged on the receiving surface and/or the emitting surface of the receiver lens, which is conducive to reducing the size of the LiDARand reducing the manufacturing cost of the LiDAR. The extinction layer may be attached to the receiver lensby plating or coating, which is not limited.

In some embodiments, if a first extinction deviceis provided between the beam splitterand the receiver lens groupalong the transmission path of the echo light, then the first extinction deviceis attached to: a receiving surface of the receiver lens groupthat is closest to the beam splitter. If a first extinction deviceis provided between two adjacent receiver lensesalong the transmission path of the echo light, then the first extinction deviceis attached to: an emitting surface of a receiver lensof the two adjacent receiver lensesthat is close to the beam splitter, or a receiving surface of a receiver lensof the two adjacent receiver lensesthat is far from the beam splitter. If a first extinction deviceis provided between the receiver lens groupand the receiveralong the transmission path of the echo light, then the first de-extinction deviceis attached to: an emitting surface of the receiver lens groupthat is closest to the receiver.

It should be noted that if the LiDARincludes multiple first extinction device, all of the first extinction devicecan use light extinction sheets, or all of the first extinction devicecan use extinction layers, or some of the first attenuator can use light extinction sheets and the remaining first extinction devicecan use extinction layers, and there is no limitation on this.

In the present embodiment of the application, referring to, a first extinction deviceis provided between the beam splitterand the receiver lens groupalong the transmission path of the echo light, and extinction teethare provided in the non-primary optical path regions between the receiver lens groupand the receiveralong the transmission path of the echo light. The first extinction devicemay include a first extinction portion, or may include a first extinction portionand a second extinction portion. The extinction teethcan be made of materials with reflectivity less than or equal to the fifth predetermined value. The fifth preset value can be selected according to actual needs. For example, the fifth preset value can be 1%, 3%, 5%, 7%, 9%, etc., without limitation.

Referring to, the LiDARmay include a window pane. An apertureis provided on the housing. The window panecovers the apertureand is connected to the housing. The window paneis configured to receive the emission light output by the beam splitterand emit the emission light to the target object outside the housing. The window paneis also configured to receive the echo light reflected back by the target object outside the housing, and emit the echo light to the beam splitter.

It is difficult for the window paneto reach a transmittance of 100%, and there will always be a certain reflectivity. In this way, the emission light will not be emitted from the housingbut will be reflected by the window pane, reach the beam splitterand further transmitted to the receiverthrough the beam splitter, generating a leading light, where the leading light is mainly distributed in the non-primary optical path regions. The above-mentioned designed first extinction devicecan eliminate the leading light.

Referring toand, the LiDARmay further include a transceiver module, which is located in the housing. The transceiver moduleis configured to receive the emission light output by the beam splitterand transmit the emission light to the target object outside the housing; the transceiver moduleis also configured to receive the echo light reflected by the target object outside the housingand transmit the echo light to the beam splitter. The transceiver modulemay include an optical scannerand/or a transceiver lens. The optical scannermay rotate to change the output direction of the emission light and may receive echo light input from multiple directions, which is beneficial to increase the emission field of view and the receiving field of view of the LiDAR. The optical scannermay be one or more of a rotating mirror and a prism, which is not limited thereto. The transceiver lensmay be configured to collimate the emission light, and the transceiver lensmay also be configured to converge the echo light, so as to facilitate the transmission of the echo light at a large angle to the beam splitter. The transceiver modulemay include one transceiver lensor a plurality of transceiver lenses, which is not limited thereto.

It is difficult for the transceiver module(for example, the optical scanner, the transceiver lens) to achieve a transmittance of 100%, and there will always be a certain reflectivity. This will cause the emission light to not be emitted from the housingbut to be reflected by the transceiver moduleinside the housing, reach the beam splitterand be further transmitted to the receiverthrough the beam splitter, thereby generating a leading light, where the leading light is mainly distributed in the non-primary optical path regions. The above-mentioned first extinction devicecan eliminate the leading light.

It should be noted that the LiDARof the embodiment of the present application may include the above-mentioned transceiver moduleand window paneat the same time, or may only include the transceiver modulein the transceiver moduleand the window pane, or may only include the transceiver moduleand the window pane, and there is no limitation on this.

Referring toand, the LiDARfurther includes a second extinction device, and the second extinction deviceand the receiverare respectively located on opposite sides of the beam splitter. The second extinction devicecan eliminate the optical signal reaching the side of the beam splitteraway from the receiver, and prevent the optical signal from being transmitted to the receiverthrough the beam splitter. Combined with the above records, since it is difficult for the light-transmitting portionto achieve a 100% transmittance, part of the emission light emitted by the transmitteris not transmitted through the light-transmitting portionbut is reflected by the light-transmitting portion, and is reflected back to the light-transmitting portionagain through the device on the reflection path (such as the housing), and then transmitted toward the receiverthrough the light-transmitting portionto generate a leading light. The second extinction devicecan be set to eliminate the part of the front light before it is transmitted toward the receiverthrough the beam splitter.

The second extinction devicecan be any extinction device. For example, the second extinction devicecan include a first extinction plateand a second extinction plate, both of which are arranged at an angle with the beam splitter, and the end of the first extinction plateaway from the beam splitteris connected to the end of the second extinction plateaway from the beam splitter, and the first extinction plateand the second extinction plateare arranged at an angle, and the opening angle of the first extinction plateand the second extinction plateis toward the beam splitter. In this way, the optical signal emitted toward the second extinction devicethrough the beam splittercan be received by the first extinction plateand/or the second extinction plate, and eliminated by the first extinction plateand the second extinction plate.

The above-mentioned design of the first extinction plateand the second extinction platebeing arranged at an angle can make it possible for the optical signal received through the first extinction plateto be absorbed and eliminated at least partially through the first extinction plate, and the remaining part can be reflected to the second extinction plateand absorbed and eliminated again through the second extinction plate, or, after the optical signal received through the second extinction plateis absorbed and eliminated at least partially through the second extinction plate, the remaining part can be reflected to the first extinction plateand absorbed and eliminated again through the first extinction plate, thereby increasing the number of times the signal is absorbed and reflected, and making the signal extinction effect better. The angle between the first extinction plateand the second extinction platecan be selected in combination with actual needs, for example, it can be set at an angle of 45°, 60°, 75°, 90°, etc., and there is no limitation on this. The angle between the above-mentioned first extinction plate/second extinction plateand the beam splittercan be selected in combination with actual needs, and there is no limitation on this.

The first extinction plateand the second extinction platecan be made of a material with a reflectivity less than or equal to the sixth preset value. The sixth preset value can be selected according to actual needs; for example, the sixth preset value can be 1%, 3%, 5%, 7%, 9%, etc., which is not limited. At least one of the first extinction plateand the second extinction platecan also be provided with extinction teeth to improve the extinction effect.

A light-collecting side of the receivercan be provided with an extinction frame, and a light-through hole is provided on the extinction frame, so that the optical signal in the non-primary optical path regions can be blocked by the extinction frame, and the optical signal in the primary optical path regions can be received by the receiverthrough the light-through hole.

In a second aspect, referring to, the embodiment of the present application further provides a movable device, which includes a device bodyand the above-mentioned LiDAR, and the device bodyis connected to the LiDAR. In the embodiment of the present application, the movable deviceis a vehicle; of course, in other embodiments of the present application, the movable devicecan also be any mobile tool equipped with the above-mentioned LiDAR, such as an electric vehicle, a drone, a robot, etc.

In the description of the present application, it should be understood that the terms “first,” “second,” etc. are configured for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, “multiple” refers to at least two, for example, two, three, four, etc. “And/or” describes the association relationship of associated objects, indicating that three relationships may exist, for example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character “/” generally indicates that the objects associated before and after are in an “or” relationship.

The above disclosure is only the preferred embodiment of the present application, which certainly cannot be configured to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.